across to us in the darkness from the waste of swamps and willows opposite. It was repeated at regular intervals, but it was certainly neither the sound of a bell nor the hooting of a distant steamer. I can liken it to nothing so much as to the sound of an immense gong, suspended far up in the sky, repeating incessantly its muffled metallic note, soft and musical, as it was repeatedly struck. My heart quickened as I listened.

"I've heard it all day," said my companion. "While you slept this afternoon it came all round the island. I hunted it down, but could never get near enough to see—to localize it correctly. Sometimes it was overhead, and sometimes it seemed under the water. Once or twice, too, I could have sworn it was not outside at all, but within myself—you know—the way a sound in the fourth dimension is supposed to come."